Patent GB-191230084-A (GB)
Title: Improvements in Sound-reproducing Instruments.
Inventor: SMITH BENJAMIN RATHBONE
Filed: 1912-12-31
Granted: 1913-12-24
Abstract: 30,084. Smith, B. R. Dec. 31. Phonographs etc.; driving and stopping. - Sound reproducing machines are provided with a tilting shelf which raises the sound-box at the end of the reproduction, a n d restores it to its original position, means being provided to repeat the performance indefinitely, o r t o arrest the machine immediately, or after any predetermined number of reproductions. Fig. 2 shows the general arrangement of the restoring-device, which consists of a substantially V-shaped flat member 25 encircling an extension 32 of the turntable spindle, and projecting beyond the edge of the disk, where it is bent downwards and hinged at 30 to a fixed bracket. A pivoted bar 94, adjustable by a rack and pinion 84, 85, projects across the opening in the shelf, and is engaged at the end of the reproduction by a projection on a bracket secured to the tone-arm. A block 93 on the bar 94 thus swings over a bent lever 60, 59, pivoted at 61 to the shelf, and limited in its movement by a pin and slot 64, 63. A spring-controlled trigger 66 normally holds the bent lever in the position shown. A small deflexion of the part 94 brings the nose 69 of the part 59 past the point 68 of the trigger, which then, by engagement with the inclined face 71 as shown, pulls the bent lever to its other extreme position. This action brings an edge 56, on a bolt 50 which slides upon the shelf, into engagement with a screw-thread 32, Fig. 6, formed upon an extension 33 of the turntable spindle. The continued rotation of the table thus causes the bolt to be lifted by the screw, so titling the shelf, which then lifts the sound-box from the record, an adjustable roller mounted thereon causing it to run down the incline to its starting position. A spring buffer 105, reversibly mounted on a non-central bolt 111 to adapt it for use with large or small records, brings the sound-box to rest. In rising, the increasing inclination of the shelf pushes back the bolt 50, and with it the lever 59, until it runs off the top of the screw-thread, while the part 68 again engages behind the part 69 and completes the disengagement of the bolt when the shelf drops, being checked by a dash-pot 122. The reproduction is then repeated, or the machine is stopped, according to the setting of the arresting-device, which is operated by the movement of the shelf. A segmental plate 138, Fig. 12, pivoted at 137, is raised by a spring when the shelf 25 is lifted, and in its return movement operates a ratchet-wheel 153 through a pawl 156. This ratchet-wheel carries a pin 171, Fig. 10, which moves in an aperture 172 in a plate 160, which carries the brake-block, so that the clockwise motion of the ratchet due to the pawl 156 finally results in the plate 160 being thrown over and the machine stopped. The number of strokes of the pawl 156 which this requires, and hence the number of reproductions which first take place, is determined by the previous setting of an external stop bearing an indicator. When a new disk is fitted, the shelf 25 is raised high enough to release the driving-pawl 156 and the check-pawl 159, and the ratchet-wheel is rotated by a spring 180 in an anti-clockwise direction until the pin 171 meets the setting-stop. To repeat the performance indefinitely, the stop is so placed that the wheel 153 is rotated backwards on setting until the pawl 156 comes upon a smooth portion of its periphery.